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// Copyright 2014 The Flutter Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
import 'dart:async';
import 'package:flutter/material.dart';
import 'recorder.dart';
/// Creates a [PageView] that uses a font style that can't be rendered
/// using canvas (switching to DOM).
///
/// Since the whole page uses a CustomPainter this is a good representation
/// for apps that have pictures with large number of painting commands.
class BenchPageViewScrollLineThrough extends WidgetRecorder {
BenchPageViewScrollLineThrough() : super(name: benchmarkName);
static const String benchmarkName = 'bench_page_view_scroll_line_through';
@override
Widget createWidget() => const MaterialApp(
title: 'PageView Scroll LineThrough Benchmark',
home: _MyScrollContainer(),
);
}
class _MyScrollContainer extends StatefulWidget {
const _MyScrollContainer();
@override
State<_MyScrollContainer> createState() => _MyScrollContainerState();
}
class _MyScrollContainerState extends State<_MyScrollContainer> {
static const Duration stepDuration = Duration(milliseconds: 500);
late PageController pageController;
final _CustomPainter _painter = _CustomPainter('aa');
int pageNumber = 0;
@override
void initState() {
super.initState();
pageController = PageController();
// Without the timer the animation doesn't begin.
Timer.run(() async {
while (pageNumber < 25) {
await pageController.animateToPage(pageNumber % 5,
duration: stepDuration, curve: Curves.easeInOut);
pageNumber++;
}
});
}
@override
void dispose() {
pageController.dispose();
_painter._textPainter.dispose();
super.dispose();
}
@override
Widget build(BuildContext context) {
return PageView.builder(
controller: pageController,
itemBuilder: (BuildContext context, int position) {
return CustomPaint(
painter: _painter,
size: const Size(300, 500),
);
});
}
}
class _CustomPainter extends CustomPainter {
_CustomPainter(this.text);
final String text;
final Paint _linePainter = Paint();
final TextPainter _textPainter = TextPainter();
static const double lineWidth = 0.5;
@override
void paint(Canvas canvas, Size size) {
canvas.clipRect(Rect.fromLTWH(0, 0, size.width, size.height));
double xPosition, yPosition;
final double width = size.width / 7;
final double height = size.height / 6;
xPosition = 0;
const double viewPadding = 5;
const double circlePadding = 4;
yPosition = viewPadding;
_textPainter.textDirection = TextDirection.ltr;
_textPainter.textWidthBasis = TextWidthBasis.longestLine;
_textPainter.textScaleFactor = 1;
const TextStyle textStyle =
TextStyle(color: Colors.black87, fontSize: 13, fontFamily: 'Roboto');
_linePainter.isAntiAlias = true;
for (int i = 0; i < 42; i++) {
_linePainter.color = Colors.white;
TextStyle temp = textStyle;
if (i % 7 == 0) {
temp = textStyle.copyWith(decoration: TextDecoration.lineThrough);
}
final TextSpan span = TextSpan(
text: text,
style: temp,
);
_textPainter.text = span;
_textPainter.layout(maxWidth: width);
_linePainter.style = PaintingStyle.fill;
canvas.drawRect(
Rect.fromLTWH(xPosition, yPosition - viewPadding, width, height),
_linePainter);
_textPainter.paint(
canvas,
Offset(xPosition + (width / 2 - _textPainter.width / 2),
yPosition + circlePadding));
xPosition += width;
if (xPosition.round() >= size.width.round()) {
xPosition = 0;
yPosition += height;
}
}
_drawVerticalAndHorizontalLines(
canvas, size, yPosition, xPosition, height, width);
}
void _drawVerticalAndHorizontalLines(Canvas canvas, Size size,
double yPosition, double xPosition, double height, double width) {
yPosition = height;
_linePainter.strokeWidth = lineWidth;
_linePainter.color = Colors.grey;
canvas.drawLine(const Offset(0, lineWidth), Offset(size.width, lineWidth),
_linePainter);
for (int i = 0; i < 6; i++) {
canvas.drawLine(
Offset(0, yPosition), Offset(size.width, yPosition), _linePainter);
yPosition += height;
}
canvas.drawLine(Offset(0, size.height - lineWidth),
Offset(size.width, size.height - lineWidth), _linePainter);
xPosition = width;
canvas.drawLine(const Offset(lineWidth, 0), Offset(lineWidth, size.height),
_linePainter);
for (int i = 0; i < 6; i++) {
canvas.drawLine(
Offset(xPosition, 0), Offset(xPosition, size.height), _linePainter);
xPosition += width;
}
}
@override
bool shouldRepaint(CustomPainter oldDelegate) {
return true;
}
}